I. Field of the Invention
The present invention relates generally to an opposed piston internal combustion four-cycle engine and, more particularly to such an engine having rotary intake and exhaust valve members.
II. Description of the Prior Art
There have been a number of previously known opposed piston internal combustion engines, mainly for two-cycle operation. In an opposed piston engine, a pair of piston members are slidably disposed in a facing relationship within a single engine cylinder so that the combustion chamber is defined between the heads of the piston members. The piston members reciprocate away from and toward each other in synchronism and, in doing so, provide the driving output from the engine.
Opposed piston engines, however, have not enjoyed widespread commercial success for a number of different reasons. For example, opposed piston four-cycle engines have also presented special difficulties with the valving of both the fuel air mixture into the combustion chamber and the exhausting of the combustion products from the engine cylinder. Previous attempts to adapt poppet valves have proven largely unsuccessful since the poppet valves cannot be positioned above the piston head as in the more conventional internal combustion engines.
The introduction of fuel into the cylinder and the exhaustion of combustion fumes therefrom have presented special problems with opposed piston diesel engines. In such engines the clearance space between the piston heads at maximum compression is too small to enable the use of poppet valves. Consequently, there have been no previously-known opposed piston diesel engines known to Applicant.